I guess the idea behind this question is that when you pour enough water on a fire, it vanishes.

So the question is, "what if we tried to extinguish the sun with water?"

Okay, so what can be said about this question.

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We will start by answering that in terms of chemistry, absolutely everything that is assumed before writing the question is FALSE. Because :

• 1/ the sun is not a fire. A fire is electromagnetic radiation that comes from combustion. Combustion is an exothermic chemical transformation. A chemical transformation is a set of molecular modifications: that is, in chemistry atoms are not created and are not destroyed, but they just combine in a different way.
• 2/ bringing water to a fire does not extinguish it. Liquid water will transform into water in the state of gas (water vapor) and this transformation will dissipate just a little of the energy of the fire, but a fire only propagates by focusing its radiant energy on a small volume of matter. But water by being transparent to these radiations, it is almost the worst candidate to stop them (a concrete block for example would work infinitely better). Bringing water around the fire therefore just prevents the temperature rise in these specific places, which will delay their future conflagration. A fire that is brought with water is therefore hampered in its spread, but it will continue to burn anything that was already ablaze.
• 3/ on Earth the usual fires that we know react on the one hand with oxygen, with on the other hand the matter that we see glowing. A fire is therefore a chemical transformation of oxidation, which is why it is possible to stop a fire of this type simply by depriving it of oxygen. It is for example what a fire extinguisher does, which does not contain water: it smothers the fire. However in space, there is no oxygen, so no star could function over time with this type of reaction: chemical.
• 4/ So what makes the sun shine is something else: by gravity, light atoms merge into heavier atoms. The engine of a star is therefore nuclear fusion, as in a fusion bomb. And the fuel is therefore light atoms (gas, liquids), which in fusion reactions will become heavier atoms (minerals, metals).
• 5/ but what is water made of? H2O: these are 2 gases, hydrogen and oxygen. Bringing water to a star such as the sun therefore provides it with fuel: it will just shine for longer!

So was this the desired effect? I don’t think so.

;-)